Nasa’s Kepler Space Telescope, having successfully completed its 3 1/2 year primary mission, now takes on a new task. Seeking out and finding true sun-Earth analogs — Earth-size planets with a one-year orbit around stars similar to the sun.

Scientists at Nasa reported yesterday that the primary mission of the Kepler space Telescope had been achieved, and that it would now search for new exoplanets.

Kepler has identified 2300 + planetary bodies with well over one hundred of them in the inhabitable zone, a region described as a zone of planets where liquid water may exist near the surface of that planet.

Now that the primary objective has been realized, Kepler will now begin seeking out Earth Analogs.

“The initial discoveries of the Kepler mission indicate at least a third of the stars have planets and the number of planets in our galaxy must number in the billions,” said Kepler principal investigator William Borucki, “The planets of greatest interest are other Earths and these could already be in the data awaiting analysis. Kepler’s most exciting results are yet to come.”

Kepler uses a different type of technology to assess a planet as well as the size of the planet. It looks at distant suns, and as objects pass through that suns light emission, it measures the absence of the light and the time it takes to get back to its original light spectrum.

The Kepler Space Telescope was launched on March 6th, 2009, its primary objective to survey those portions of the Milky Way Galaxy that may include Goldilocks type planets, those that might be considered habitable. After 2 months of positioning, Kepler began sending back data in mid-May 2009, and discovered 5 new planets in a relatively short period of time, much to the delight of the scientists at NASA.

The secondary objective would be to find planets similar to Earth, with a one year orbit around their sun, and not in too close of a proximity to that sun as to make that planet too hot for habitation.

As reported at www.nasa.gov, highlights from the primary mission include:

— In August 2010, scientists confirmed the discovery of the first planetary system with more than one planet transiting the same star. The Kepler-9 system opened the door to measurement of gravitational interactions between planets as observed by the variations in their transit timing. This powerful new technique enables astronomers, in many cases, to calculate the mass of planets directly from Kepler data, without the need for follow-up observations from the ground.

— In February 2011, scientists announced Kepler had found a very crowded and compact planetary system – a star with multiple transiting planets. Kepler-11 has six planets larger than Earth, all orbiting closer to their star than Venus orbits our sun. This and other subsequently identified compact multi-planet systems have orbital spacing relative to their host sun and neighboring planets unlike anything envisioned prior to the mission.

— In September 2011, Kepler data confirmed the existence of a world with a double sunset like the one famously portrayed in the film “Star Wars” more than 35 years ago. The discovery of Kepler-16b turned science fiction into science fact. Since then, the discoveries of six additional worlds orbiting double stars further demonstrated planets can form and persist in the environs of a double-star system.

— In December 2011, NASA announced Kepler’s discovery of the mission’s first planet in a habitable zone. Kepler-22b, about 2.4 times the size of Earth, is the smallest-radius planet yet found to orbit a sun-like star in the habitable zone. This discovery confirmed that we are getting continually closer to finding planets like our own.

“Kepler’s bounty of new planet discoveries, many quite different from anything found previously, will continue to astound,” said Planetary Scientist Jack Lissauer, “But to me, the most wonderful discovery of the mission has not been individual planets, but the systems of two, three, even six planets crowded close to their stars, and, like the planets orbiting about our sun, moving in nearly the same plane. Like people, planets interact with their neighbors and can be greatly affected by them. What are the neighborhoods of Earth-size exoplanets like? This is the question I most hope Kepler will answer in the years to come.”

In April 2012, NASA extended Kepler’s mission through late 2016. More time will enable the continued the search for worlds like our own — worlds that are not too far and too close to their sun.

“The Earth isn’t unique, nor the center of the universe,” said Geoff Marcy, professor of astronomy at UC Berkeley. “The diversity of other worlds is greater than depicted in all the science fiction novels and movies. Aristotle would be proud of us for answering some of the most profound philosophical questions about our place in the Universe.”

Ames manages Kepler’s ground system development, mission operations and science data analysis. NASA’s Jet Propulsion Laboratory in Pasadena, Calif., managed the Kepler mission development. Ball Aerospace & Technologies Corp. in Boulder, Colo., developed the Kepler flight system and supports mission operations with the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder. The Space Telescope Science Institute in Baltimore archives, hosts and distributes Kepler science data. Kepler is NASA’s 10th Discovery Mission and funded by NASA’s Science Mission Directorate at the agency’s headquarters in Washington.